today on gun violence. 104 days after the shooting in newtown, connecticut. Today the president called for change, surrounded by families of murdered children. Among them, families from newtown, who learned today that the shooter, adam lans a gunned down 20 children in under five minutes. Here's abc's white house correspondent jim avila. Reporter: Until today these brutal facts were sealed by the court. Gunman adam lanza was not a teenager. He was 20 years old. He fired 154 shots in two, not as much originally reported, three newtown classrooms. Five search warrants reveal today he did not wear a bullet-proof vest. Only military-style clothing. His bushmaster semiautomatic rifle was accessorized with 30-round magazines, giving him access to thousands of rounds. At home where lanza lived with his mother, the police search found two nra certificates in the names of nancy and adam lanza, even though the nra vehemently denies they were members. Nine knives, three swords, and a bb gun. A holiday card from his mother containing an uncashed check to buy a new gun. And also revealed today, testimony from an unknown neighbor that lanza spent lots of time in his basement, playing violent video games. Every detail that I hear about that day is painful. So I prefer to focus less on what was found in the house and the car, and more on what we can do to make changes so this doesn't happen again in the future. Reporter: Across the country today from san francisco to newtown, demonstrations calling on congress to take action. New york mayor michael bloomberg, releasing $12 million in new tv commercials today, calling for new gun laws. This time featuring newtown families. She just wanted to teach little kids. That was her goal, and she died doing it. Wonderful. Reporter: And at the white house, an emotional east room. Tears and presidential hugs for victims of gun crime from places like newtown, virginia tech, and chicago. President obama, unusually passionate and appearing concerned that momentum for gun reform has stalled on capitol hill. Shame on us if we've forgotten. I haven't forgotten those kids. Reporter: The president promising to keep the pressure on congress, to pass an assault

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